1. Field
The disclosed embodiments relate to the field of power generation based on combustion of a fuel.
2. Related Art
Traditional systems and methods for generating power based on combustion of a fuel suffer from a number of drawbacks.
A traditional internal combustion engine (ICE), for example, generates more heat than it effectively can convert to mechanical work. An undesirable side effect is that its components will be damaged by high temperatures unless the heat is removed by an air or liquid cooling system. In typical ICE automotive applications 15% of the fuel energy is lost through the radiator alone. Moreover, about 80%-87% of the chemical energy in fuel is wasted overall in ICEs, mostly as hot gases and un-burnt fuel vented from the exhaust stream. This corresponds to an energy utilization of typically 13% (urban driving) or 20% (highway driving) of the fuel energy reaching the axle.
ICE technology produces low torque at low speed which leads to a scale mismatch between time averaged power utilization and on demand low speed performance requirements. An oversized engine is required to compensate, enabling adequate low speed functionality. It also requires a complicated power transmission system and gear box to provide adequate torque throughout the useful operating range. The combination of an oversized engine and the mechanical inefficiencies of the power transmission system contribute to the inefficient use of energy.
Modern ICE technologies also require processing exhaust gases with a catalytic converter to remove unburned fuel, nitrous oxides (NOx), and soot before being released to the atmosphere. Converter backpressure actively robs mechanical energy from the engine. It also represents an opportunity loss by the fact that heat and vapors generated in the converter aren't harnessed for productive work. In an automobile a hot catalytic converter presents a fire hazard for combustible debris under a vehicle and so contributes to the rate of accidental automobile fires. Typically exhaust heat and subsequent chemical reactions heat the catalyst interior to greater than 700° F., spilling the waste heat to the ambient air through the converter walls and out the tailpipe. Further, in an ICE, air must be compressed before combustion is possible. Useful energy production from the expanding gases is diminished by their compression. Net productivity effectively results only from the incremental gas product formed by combustion.